Camera system

Abstract

A camera system exhibiting reduced effects from temperature changes. The camera system includes an IR sensor; an optical arrangement adapted to focus incoming light onto the sensor; a processing arrangement adapted to process signals produced by the sensor; a heatsink in thermal contact with and is adapted to transfer heat energy away from, the processing arrangement; and a thermal equalizer. The thermal equalizer at least partially surrounds and is in thermal contact with the optics/sensor unit and is formed at least partially from a material having a high thermal conductivity. The thermal equalizer conducts heat energy from warmer to cooler parts of the optics/sensor unit. The thermal equalizer is also thermally insulated from ambient air surrounding the camera system and from the heatsink.

1. A camera system comprising:
 an IR sensor; 
 an optical arrangement adapted to focus incoming light onto the sensor, the sensor and the optical arrangement together forming an optics/sensor unit; 
 a processing arrangement configured to process signals produced by the sensor; 
 a heatsink which is in thermal contact with, and is adapted to transfer heat energy away from, the processing arrangement; and 
 a thermal equalizer, formed at least partially from a material having a high thermal conductivity, which at least partially surrounds, and is in thermal contact with, the optics/sensor unit and is operable to conduct heat energy from warmer to cooler parts of the optics/sensor unit, 
 the thermal equalizer being thermally Insulated from ambient air surrounding the camera system and from the heatsink. 
 
     
     
       2. A camera system according  claim 1 , wherein the thermal equalizer is thermally insulated from ambient air surrounding the camera system by means of a layer of air which at least partially surrounds the thermal equalizer. 
     
     
       3. A camera system according to  claim 2 , wherein the layer of air is enclosed within an outer housing. 
     
     
       4. A camera system according to  claim 1 , wherein the thermal equalizer is thermally insulated from the heatsink by means of an insulating layer provided between the thermal equalizer and the heatsink. 
     
     
       5. A camera system according to  claim 1 , wherein the heatsink comprises a substantially planar sheet of material. 
     
     
       6. A camera system according to  claim 5 , wherein the heatsink further comprises a lip which extends from the edges of the sheet at approximately right-angles thereto. 
     
     
       7. A camera system according to  claim 1 , further comprising an external housing having front and rear parts, the front part containing the optics/sensor system and the thermal equalizer, and the rear part containing the processing electronics. 
     
     
       8. A camera system according to  claim 7 , wherein the front and rear parts of the external housing are separated by the heatsink. 
     
     
       9. A camera system according to  claim 8 , wherein a part of the heatsink forms part of the outer surface of the camera system, the part of the heatsink separating the front and rear parts of the external housing. 
     
     
       10. A vehicle comprising a camera system according to  claim 1 . 
     
     
       11. A camera system comprising:
 an IR sensor; 
 an optical arrangement adapted to focus incoming light onto the sensor, the sensor and the optical arrangement together forming an optics/sensor unit; 
 a processing arrangement adapted to process signals produced by the sensor; 
 a heatsink which is in thermal contact with, and is adapted to transfer heat energy away form, the processing arrangement; and 
 a thermal egualizer, formed at least partially from a material having a high thermal conductivity, which at least partially surrounds, and is in thermal contact with, the optics/sensor unit and is operable to conduct heat energy from warmer to cooler parts of the optics/sensor unit, the thermal equalizer including a substantially planar plate portion which is in thermal contact with the IR sensor, the thermal equalizer being thermally insulated from ambient air surrounding the camera system and from the heatslnk. 
 
     
     
       12. A camera system according to  claim 11 , wherein the thermal equalizer further comprises a substantially cylindrical, hollow protrusion which at least partly surrounds the optical arrangement, and is in thermal contact with the plate portion of the thermal equalizer. 
     
     
       13. A camera system comprising:
 an IR sensor; 
 an optical arrangement adapted to focus incoming light onto the sensor, the sensor and the optical arrangement together forming an optics/sensor unit; 
 a processing arrangement adapted to process signals produced by the sensor; 
 a heatsink which is in thermal contact with, and is adapted to transfer heat energy away from, the processing arrangement; and 
 a thermal equalizer, formed at least partially from a material having a thermal conductivity that is equal to or higher than that of zinc, which at least partially surrounds, and is in thermal contact with, the optics/sensor unit and is operable to conduct heat energy from warmer to cooler parts of the optics/sensor unit, the thermal equalizer being thermally insulated from ambient air surrounding the camera system and from the heatsink. 
 
     
     
       14. A camera system comprising:
 an IR sensor 
 an optical arrangement adapted to focus incoming light onto the sensor, the sensor and the optical arrangement together forming an optics/sensor unit; 
 a processing arrangement adapted to process signals produced by the sensor; 
 a heatsink which is in thermal contact with, and is adapted to transfer heat energy away from, the processing arrangement; and 
 a thermal equalizer, formed at least partially from a material having a high thermal conductivity which at least partially surrounds, and is in thermal contact with, the optics/sensor unit and is operable to conduct heat energy from warmer to cooler parts of the optics/sensor unit, 
 the thermal equalizer being thermally insulated from ambient air surrounding the camera system and from the heatsink; and 
 wherein the thermal equalizer is at least partially formed from a material having a specific heat capacity which is equal to or higher than that of zinc.